The 27th of Rajab and the Practice of the Prophet S
It is narrated on the authority of Abu Huraira R that the Holy Prophet said:"If someone keeps the fast on the twenty-seventh day of Rajab, he will be credited with the same reward as that which is earned by fasting for sixty months." And it was on this day that Jibraeel alayhis salaam first came down to invest the Holy Prophet with Messengership. [Ibn al-Mubarik al-Saqati]
Abu Huraira R and Salman al-Farsi R said that the Holy Prophet said: "Rajab contains a very special day and a very special night. If someone fasts during that day, and keeps vigil throughout that night, he will be entitled to a reward like the one that would be
earned by a person who fasted for a hundred years, and who kept vigil throughout all the nights in that period." [Baihaqi]
It is narrated from Al-Hasan al-Basri R, who said: "Whenever the twenty-seventh of Rajab came around, Abdullah ibn Abbas R would start the day in i’takif. He would devote the whole morning to prayer, up to and including the obligatory ritual prayer at noon [Dhuhr]. After performing the noon prayer, he would stroll about for a little while to stretch his legs, then he would perform an extra salat-prayer consisting of four cycles. In each cycle [rak'a], he would recite Surah Al-Fatiha one time only, then Surah Al-Falaq & Surah An-Naas [Al-Mu'awwidhataan], also one time only, then Surah Al-Qadr [#97] three times, and then Surah Al-Ikhlaas fifty times. He would then devote himself to continuous supplication [du'a], until it was time to perform the obligatory late-afternoon ritual prayer (‘Asr). ‘This,’ he used to say, ‘is exactly what Allah’s Messenger S always did on this particular day.’" [Ibn al-Mubarik al-Saqati]
Sh. Abdul Qadir Jilani R writes in the Ghunya that the scholars have deemed the following 14 nights for all night worship, and fasting [except where fasting is not permissible, i.e. the 2 eids, and refers to night vigil only on those days]:
1. The 1st of Muharram
2. The 10th of Muharram (Ashura)
3. The 1st of Rajab
4. The 15th of Rajab
5. The 27th of Rajab
6. The 15th of Sha’ban
7. The 1st of Shawwal (Eid-ul-Fitr)
8. The 9th of Dhul Hijjah (Arafa)
9. The 10th of Dhul Hijjah
10. The 21st of Ramadan
11. The 23rd of Ramadan
12. The 25th of Ramadan
13. The 27th of Ramadan
14. The 29th of Ramadan
Source: Shaykh Abdul-Qadir Jilani R Al-Ghunyatu li Taalibi Tareeq il Haqq
